AT&T says it will make available a $40 prepaid rate plan for feature phones through its newly acquired Cricket brand that includes unlimited talk, text, and data.

According to a filing with the FCC that's intended to keep the commission up to date on the progress AT&T's merger with Cricket parent company Leap Wireless, the plan will be available at a rate that will not exceed $40 per month for 18 months following the close of the merger.

That plan would appear to undercut by $5 a comparable plan Cricket currently offers, which includes unlimited talk, text and data for $45. Cricket also offers a $5 discount on existing plans for those customer who set up automatic payments.

The company's CEO Randall Stephenson said yesterday that AT&T intends to use the Cricket brand to disrupt the lower end of the market. He also wouldn't rule out a postpaid offering under the brand but stressed that initially Cricket would remain a pure prepaid play.

AT&T back in July of 2013 agreed to acquire Leap Wireless for about $1.19 billion in cash or $15 a share. Leap's Cricket brand has approximately 5 million subscribers. The deal also allows AT&T to deploy LTE on the company AWS and PCS spectrum.

As part of its merger agreement, AT&T has provided the FCC with detailed estimates of where it anticipates it will begin deploying Leap’s AWS-1 spectrum for LTE service within 90 days of the merger’s closing and where it anticipates it will begin deploying Leap’s unused AWS or PCS spectrum for LTE service within 12 months of the merger’s closing.